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authorIngo Molnar <mingo@elte.hu>2009-06-11 23:31:52 +0200
committerIngo Molnar <mingo@elte.hu>2009-06-11 23:31:52 +0200
commit0d5959723e1db3fd7323c198a50c16cecf96c7a9 (patch)
tree802b623fff261ebcbbddadf84af5524398364a18 /arch/powerpc/kernel/perf_counter.c
parent62fdac5913f71f8f200bd2c9bd59a02e9a1498e9 (diff)
parent512626a04e72aca60effe111fa0333ed0b195d21 (diff)
Merge branch 'linus' into x86/mce3
Conflicts: arch/x86/kernel/cpu/mcheck/mce_64.c arch/x86/kernel/irq.c Merge reason: Resolve the conflicts above. Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/powerpc/kernel/perf_counter.c')
-rw-r--r--arch/powerpc/kernel/perf_counter.c1263
1 files changed, 1263 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/perf_counter.c b/arch/powerpc/kernel/perf_counter.c
new file mode 100644
index 00000000000..bb202388170
--- /dev/null
+++ b/arch/powerpc/kernel/perf_counter.c
@@ -0,0 +1,1263 @@
+/*
+ * Performance counter support - powerpc architecture code
+ *
+ * Copyright 2008-2009 Paul Mackerras, IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/perf_counter.h>
+#include <linux/percpu.h>
+#include <linux/hardirq.h>
+#include <asm/reg.h>
+#include <asm/pmc.h>
+#include <asm/machdep.h>
+#include <asm/firmware.h>
+#include <asm/ptrace.h>
+
+struct cpu_hw_counters {
+ int n_counters;
+ int n_percpu;
+ int disabled;
+ int n_added;
+ int n_limited;
+ u8 pmcs_enabled;
+ struct perf_counter *counter[MAX_HWCOUNTERS];
+ u64 events[MAX_HWCOUNTERS];
+ unsigned int flags[MAX_HWCOUNTERS];
+ u64 mmcr[3];
+ struct perf_counter *limited_counter[MAX_LIMITED_HWCOUNTERS];
+ u8 limited_hwidx[MAX_LIMITED_HWCOUNTERS];
+};
+DEFINE_PER_CPU(struct cpu_hw_counters, cpu_hw_counters);
+
+struct power_pmu *ppmu;
+
+/*
+ * Normally, to ignore kernel events we set the FCS (freeze counters
+ * in supervisor mode) bit in MMCR0, but if the kernel runs with the
+ * hypervisor bit set in the MSR, or if we are running on a processor
+ * where the hypervisor bit is forced to 1 (as on Apple G5 processors),
+ * then we need to use the FCHV bit to ignore kernel events.
+ */
+static unsigned int freeze_counters_kernel = MMCR0_FCS;
+
+static void perf_counter_interrupt(struct pt_regs *regs);
+
+void perf_counter_print_debug(void)
+{
+}
+
+/*
+ * Read one performance monitor counter (PMC).
+ */
+static unsigned long read_pmc(int idx)
+{
+ unsigned long val;
+
+ switch (idx) {
+ case 1:
+ val = mfspr(SPRN_PMC1);
+ break;
+ case 2:
+ val = mfspr(SPRN_PMC2);
+ break;
+ case 3:
+ val = mfspr(SPRN_PMC3);
+ break;
+ case 4:
+ val = mfspr(SPRN_PMC4);
+ break;
+ case 5:
+ val = mfspr(SPRN_PMC5);
+ break;
+ case 6:
+ val = mfspr(SPRN_PMC6);
+ break;
+ case 7:
+ val = mfspr(SPRN_PMC7);
+ break;
+ case 8:
+ val = mfspr(SPRN_PMC8);
+ break;
+ default:
+ printk(KERN_ERR "oops trying to read PMC%d\n", idx);
+ val = 0;
+ }
+ return val;
+}
+
+/*
+ * Write one PMC.
+ */
+static void write_pmc(int idx, unsigned long val)
+{
+ switch (idx) {
+ case 1:
+ mtspr(SPRN_PMC1, val);
+ break;
+ case 2:
+ mtspr(SPRN_PMC2, val);
+ break;
+ case 3:
+ mtspr(SPRN_PMC3, val);
+ break;
+ case 4:
+ mtspr(SPRN_PMC4, val);
+ break;
+ case 5:
+ mtspr(SPRN_PMC5, val);
+ break;
+ case 6:
+ mtspr(SPRN_PMC6, val);
+ break;
+ case 7:
+ mtspr(SPRN_PMC7, val);
+ break;
+ case 8:
+ mtspr(SPRN_PMC8, val);
+ break;
+ default:
+ printk(KERN_ERR "oops trying to write PMC%d\n", idx);
+ }
+}
+
+/*
+ * Check if a set of events can all go on the PMU at once.
+ * If they can't, this will look at alternative codes for the events
+ * and see if any combination of alternative codes is feasible.
+ * The feasible set is returned in event[].
+ */
+static int power_check_constraints(u64 event[], unsigned int cflags[],
+ int n_ev)
+{
+ u64 mask, value, nv;
+ u64 alternatives[MAX_HWCOUNTERS][MAX_EVENT_ALTERNATIVES];
+ u64 amasks[MAX_HWCOUNTERS][MAX_EVENT_ALTERNATIVES];
+ u64 avalues[MAX_HWCOUNTERS][MAX_EVENT_ALTERNATIVES];
+ u64 smasks[MAX_HWCOUNTERS], svalues[MAX_HWCOUNTERS];
+ int n_alt[MAX_HWCOUNTERS], choice[MAX_HWCOUNTERS];
+ int i, j;
+ u64 addf = ppmu->add_fields;
+ u64 tadd = ppmu->test_adder;
+
+ if (n_ev > ppmu->n_counter)
+ return -1;
+
+ /* First see if the events will go on as-is */
+ for (i = 0; i < n_ev; ++i) {
+ if ((cflags[i] & PPMU_LIMITED_PMC_REQD)
+ && !ppmu->limited_pmc_event(event[i])) {
+ ppmu->get_alternatives(event[i], cflags[i],
+ alternatives[i]);
+ event[i] = alternatives[i][0];
+ }
+ if (ppmu->get_constraint(event[i], &amasks[i][0],
+ &avalues[i][0]))
+ return -1;
+ }
+ value = mask = 0;
+ for (i = 0; i < n_ev; ++i) {
+ nv = (value | avalues[i][0]) + (value & avalues[i][0] & addf);
+ if ((((nv + tadd) ^ value) & mask) != 0 ||
+ (((nv + tadd) ^ avalues[i][0]) & amasks[i][0]) != 0)
+ break;
+ value = nv;
+ mask |= amasks[i][0];
+ }
+ if (i == n_ev)
+ return 0; /* all OK */
+
+ /* doesn't work, gather alternatives... */
+ if (!ppmu->get_alternatives)
+ return -1;
+ for (i = 0; i < n_ev; ++i) {
+ choice[i] = 0;
+ n_alt[i] = ppmu->get_alternatives(event[i], cflags[i],
+ alternatives[i]);
+ for (j = 1; j < n_alt[i]; ++j)
+ ppmu->get_constraint(alternatives[i][j],
+ &amasks[i][j], &avalues[i][j]);
+ }
+
+ /* enumerate all possibilities and see if any will work */
+ i = 0;
+ j = -1;
+ value = mask = nv = 0;
+ while (i < n_ev) {
+ if (j >= 0) {
+ /* we're backtracking, restore context */
+ value = svalues[i];
+ mask = smasks[i];
+ j = choice[i];
+ }
+ /*
+ * See if any alternative k for event i,
+ * where k > j, will satisfy the constraints.
+ */
+ while (++j < n_alt[i]) {
+ nv = (value | avalues[i][j]) +
+ (value & avalues[i][j] & addf);
+ if ((((nv + tadd) ^ value) & mask) == 0 &&
+ (((nv + tadd) ^ avalues[i][j])
+ & amasks[i][j]) == 0)
+ break;
+ }
+ if (j >= n_alt[i]) {
+ /*
+ * No feasible alternative, backtrack
+ * to event i-1 and continue enumerating its
+ * alternatives from where we got up to.
+ */
+ if (--i < 0)
+ return -1;
+ } else {
+ /*
+ * Found a feasible alternative for event i,
+ * remember where we got up to with this event,
+ * go on to the next event, and start with
+ * the first alternative for it.
+ */
+ choice[i] = j;
+ svalues[i] = value;
+ smasks[i] = mask;
+ value = nv;
+ mask |= amasks[i][j];
+ ++i;
+ j = -1;
+ }
+ }
+
+ /* OK, we have a feasible combination, tell the caller the solution */
+ for (i = 0; i < n_ev; ++i)
+ event[i] = alternatives[i][choice[i]];
+ return 0;
+}
+
+/*
+ * Check if newly-added counters have consistent settings for
+ * exclude_{user,kernel,hv} with each other and any previously
+ * added counters.
+ */
+static int check_excludes(struct perf_counter **ctrs, unsigned int cflags[],
+ int n_prev, int n_new)
+{
+ int eu = 0, ek = 0, eh = 0;
+ int i, n, first;
+ struct perf_counter *counter;
+
+ n = n_prev + n_new;
+ if (n <= 1)
+ return 0;
+
+ first = 1;
+ for (i = 0; i < n; ++i) {
+ if (cflags[i] & PPMU_LIMITED_PMC_OK) {
+ cflags[i] &= ~PPMU_LIMITED_PMC_REQD;
+ continue;
+ }
+ counter = ctrs[i];
+ if (first) {
+ eu = counter->attr.exclude_user;
+ ek = counter->attr.exclude_kernel;
+ eh = counter->attr.exclude_hv;
+ first = 0;
+ } else if (counter->attr.exclude_user != eu ||
+ counter->attr.exclude_kernel != ek ||
+ counter->attr.exclude_hv != eh) {
+ return -EAGAIN;
+ }
+ }
+
+ if (eu || ek || eh)
+ for (i = 0; i < n; ++i)
+ if (cflags[i] & PPMU_LIMITED_PMC_OK)
+ cflags[i] |= PPMU_LIMITED_PMC_REQD;
+
+ return 0;
+}
+
+static void power_pmu_read(struct perf_counter *counter)
+{
+ long val, delta, prev;
+
+ if (!counter->hw.idx)
+ return;
+ /*
+ * Performance monitor interrupts come even when interrupts
+ * are soft-disabled, as long as interrupts are hard-enabled.
+ * Therefore we treat them like NMIs.
+ */
+ do {
+ prev = atomic64_read(&counter->hw.prev_count);
+ barrier();
+ val = read_pmc(counter->hw.idx);
+ } while (atomic64_cmpxchg(&counter->hw.prev_count, prev, val) != prev);
+
+ /* The counters are only 32 bits wide */
+ delta = (val - prev) & 0xfffffffful;
+ atomic64_add(delta, &counter->count);
+ atomic64_sub(delta, &counter->hw.period_left);
+}
+
+/*
+ * On some machines, PMC5 and PMC6 can't be written, don't respect
+ * the freeze conditions, and don't generate interrupts. This tells
+ * us if `counter' is using such a PMC.
+ */
+static int is_limited_pmc(int pmcnum)
+{
+ return (ppmu->flags & PPMU_LIMITED_PMC5_6)
+ && (pmcnum == 5 || pmcnum == 6);
+}
+
+static void freeze_limited_counters(struct cpu_hw_counters *cpuhw,
+ unsigned long pmc5, unsigned long pmc6)
+{
+ struct perf_counter *counter;
+ u64 val, prev, delta;
+ int i;
+
+ for (i = 0; i < cpuhw->n_limited; ++i) {
+ counter = cpuhw->limited_counter[i];
+ if (!counter->hw.idx)
+ continue;
+ val = (counter->hw.idx == 5) ? pmc5 : pmc6;
+ prev = atomic64_read(&counter->hw.prev_count);
+ counter->hw.idx = 0;
+ delta = (val - prev) & 0xfffffffful;
+ atomic64_add(delta, &counter->count);
+ }
+}
+
+static void thaw_limited_counters(struct cpu_hw_counters *cpuhw,
+ unsigned long pmc5, unsigned long pmc6)
+{
+ struct perf_counter *counter;
+ u64 val;
+ int i;
+
+ for (i = 0; i < cpuhw->n_limited; ++i) {
+ counter = cpuhw->limited_counter[i];
+ counter->hw.idx = cpuhw->limited_hwidx[i];
+ val = (counter->hw.idx == 5) ? pmc5 : pmc6;
+ atomic64_set(&counter->hw.prev_count, val);
+ perf_counter_update_userpage(counter);
+ }
+}
+
+/*
+ * Since limited counters don't respect the freeze conditions, we
+ * have to read them immediately after freezing or unfreezing the
+ * other counters. We try to keep the values from the limited
+ * counters as consistent as possible by keeping the delay (in
+ * cycles and instructions) between freezing/unfreezing and reading
+ * the limited counters as small and consistent as possible.
+ * Therefore, if any limited counters are in use, we read them
+ * both, and always in the same order, to minimize variability,
+ * and do it inside the same asm that writes MMCR0.
+ */
+static void write_mmcr0(struct cpu_hw_counters *cpuhw, unsigned long mmcr0)
+{
+ unsigned long pmc5, pmc6;
+
+ if (!cpuhw->n_limited) {
+ mtspr(SPRN_MMCR0, mmcr0);
+ return;
+ }
+
+ /*
+ * Write MMCR0, then read PMC5 and PMC6 immediately.
+ * To ensure we don't get a performance monitor interrupt
+ * between writing MMCR0 and freezing/thawing the limited
+ * counters, we first write MMCR0 with the counter overflow
+ * interrupt enable bits turned off.
+ */
+ asm volatile("mtspr %3,%2; mfspr %0,%4; mfspr %1,%5"
+ : "=&r" (pmc5), "=&r" (pmc6)
+ : "r" (mmcr0 & ~(MMCR0_PMC1CE | MMCR0_PMCjCE)),
+ "i" (SPRN_MMCR0),
+ "i" (SPRN_PMC5), "i" (SPRN_PMC6));
+
+ if (mmcr0 & MMCR0_FC)
+ freeze_limited_counters(cpuhw, pmc5, pmc6);
+ else
+ thaw_limited_counters(cpuhw, pmc5, pmc6);
+
+ /*
+ * Write the full MMCR0 including the counter overflow interrupt
+ * enable bits, if necessary.
+ */
+ if (mmcr0 & (MMCR0_PMC1CE | MMCR0_PMCjCE))
+ mtspr(SPRN_MMCR0, mmcr0);
+}
+
+/*
+ * Disable all counters to prevent PMU interrupts and to allow
+ * counters to be added or removed.
+ */
+void hw_perf_disable(void)
+{
+ struct cpu_hw_counters *cpuhw;
+ unsigned long ret;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ cpuhw = &__get_cpu_var(cpu_hw_counters);
+
+ ret = cpuhw->disabled;
+ if (!ret) {
+ cpuhw->disabled = 1;
+ cpuhw->n_added = 0;
+
+ /*
+ * Check if we ever enabled the PMU on this cpu.
+ */
+ if (!cpuhw->pmcs_enabled) {
+ if (ppc_md.enable_pmcs)
+ ppc_md.enable_pmcs();
+ cpuhw->pmcs_enabled = 1;
+ }
+
+ /*
+ * Disable instruction sampling if it was enabled
+ */
+ if (cpuhw->mmcr[2] & MMCRA_SAMPLE_ENABLE) {
+ mtspr(SPRN_MMCRA,
+ cpuhw->mmcr[2] & ~MMCRA_SAMPLE_ENABLE);
+ mb();
+ }
+
+ /*
+ * Set the 'freeze counters' bit.
+ * The barrier is to make sure the mtspr has been
+ * executed and the PMU has frozen the counters
+ * before we return.
+ */
+ write_mmcr0(cpuhw, mfspr(SPRN_MMCR0) | MMCR0_FC);
+ mb();
+ }
+ local_irq_restore(flags);
+}
+
+/*
+ * Re-enable all counters if disable == 0.
+ * If we were previously disabled and counters were added, then
+ * put the new config on the PMU.
+ */
+void hw_perf_enable(void)
+{
+ struct perf_counter *counter;
+ struct cpu_hw_counters *cpuhw;
+ unsigned long flags;
+ long i;
+ unsigned long val;
+ s64 left;
+ unsigned int hwc_index[MAX_HWCOUNTERS];
+ int n_lim;
+ int idx;
+
+ local_irq_save(flags);
+ cpuhw = &__get_cpu_var(cpu_hw_counters);
+ if (!cpuhw->disabled) {
+ local_irq_restore(flags);
+ return;
+ }
+ cpuhw->disabled = 0;
+
+ /*
+ * If we didn't change anything, or only removed counters,
+ * no need to recalculate MMCR* settings and reset the PMCs.
+ * Just reenable the PMU with the current MMCR* settings
+ * (possibly updated for removal of counters).
+ */
+ if (!cpuhw->n_added) {
+ mtspr(SPRN_MMCRA, cpuhw->mmcr[2] & ~MMCRA_SAMPLE_ENABLE);
+ mtspr(SPRN_MMCR1, cpuhw->mmcr[1]);
+ if (cpuhw->n_counters == 0)
+ get_lppaca()->pmcregs_in_use = 0;
+ goto out_enable;
+ }
+
+ /*
+ * Compute MMCR* values for the new set of counters
+ */
+ if (ppmu->compute_mmcr(cpuhw->events, cpuhw->n_counters, hwc_index,
+ cpuhw->mmcr)) {
+ /* shouldn't ever get here */
+ printk(KERN_ERR "oops compute_mmcr failed\n");
+ goto out;
+ }
+
+ /*
+ * Add in MMCR0 freeze bits corresponding to the
+ * attr.exclude_* bits for the first counter.
+ * We have already checked that all counters have the
+ * same values for these bits as the first counter.
+ */
+ counter = cpuhw->counter[0];
+ if (counter->attr.exclude_user)
+ cpuhw->mmcr[0] |= MMCR0_FCP;
+ if (counter->attr.exclude_kernel)
+ cpuhw->mmcr[0] |= freeze_counters_kernel;
+ if (counter->attr.exclude_hv)
+ cpuhw->mmcr[0] |= MMCR0_FCHV;
+
+ /*
+ * Write the new configuration to MMCR* with the freeze
+ * bit set and set the hardware counters to their initial values.
+ * Then unfreeze the counters.
+ */
+ get_lppaca()->pmcregs_in_use = 1;
+ mtspr(SPRN_MMCRA, cpuhw->mmcr[2] & ~MMCRA_SAMPLE_ENABLE);
+ mtspr(SPRN_MMCR1, cpuhw->mmcr[1]);
+ mtspr(SPRN_MMCR0, (cpuhw->mmcr[0] & ~(MMCR0_PMC1CE | MMCR0_PMCjCE))
+ | MMCR0_FC);
+
+ /*
+ * Read off any pre-existing counters that need to move
+ * to another PMC.
+ */
+ for (i = 0; i < cpuhw->n_counters; ++i) {
+ counter = cpuhw->counter[i];
+ if (counter->hw.idx && counter->hw.idx != hwc_index[i] + 1) {
+ power_pmu_read(counter);
+ write_pmc(counter->hw.idx, 0);
+ counter->hw.idx = 0;
+ }
+ }
+
+ /*
+ * Initialize the PMCs for all the new and moved counters.
+ */
+ cpuhw->n_limited = n_lim = 0;
+ for (i = 0; i < cpuhw->n_counters; ++i) {
+ counter = cpuhw->counter[i];
+ if (counter->hw.idx)
+ continue;
+ idx = hwc_index[i] + 1;
+ if (is_limited_pmc(idx)) {
+ cpuhw->limited_counter[n_lim] = counter;
+ cpuhw->limited_hwidx[n_lim] = idx;
+ ++n_lim;
+ continue;
+ }
+ val = 0;
+ if (counter->hw.sample_period) {
+ left = atomic64_read(&counter->hw.period_left);
+ if (left < 0x80000000L)
+ val = 0x80000000L - left;
+ }
+ atomic64_set(&counter->hw.prev_count, val);
+ counter->hw.idx = idx;
+ write_pmc(idx, val);
+ perf_counter_update_userpage(counter);
+ }
+ cpuhw->n_limited = n_lim;
+ cpuhw->mmcr[0] |= MMCR0_PMXE | MMCR0_FCECE;
+
+ out_enable:
+ mb();
+ write_mmcr0(cpuhw, cpuhw->mmcr[0]);
+
+ /*
+ * Enable instruction sampling if necessary
+ */
+ if (cpuhw->mmcr[2] & MMCRA_SAMPLE_ENABLE) {
+ mb();
+ mtspr(SPRN_MMCRA, cpuhw->mmcr[2]);
+ }
+
+ out:
+ local_irq_restore(flags);
+}
+
+static int collect_events(struct perf_counter *group, int max_count,
+ struct perf_counter *ctrs[], u64 *events,
+ unsigned int *flags)
+{
+ int n = 0;
+ struct perf_counter *counter;
+
+ if (!is_software_counter(group)) {
+ if (n >= max_count)
+ return -1;
+ ctrs[n] = group;
+ flags[n] = group->hw.counter_base;
+ events[n++] = group->hw.config;
+ }
+ list_for_each_entry(counter, &group->sibling_list, list_entry) {
+ if (!is_software_counter(counter) &&
+ counter->state != PERF_COUNTER_STATE_OFF) {
+ if (n >= max_count)
+ return -1;
+ ctrs[n] = counter;
+ flags[n] = counter->hw.counter_base;
+ events[n++] = counter->hw.config;
+ }
+ }
+ return n;
+}
+
+static void counter_sched_in(struct perf_counter *counter, int cpu)
+{
+ counter->state = PERF_COUNTER_STATE_ACTIVE;
+ counter->oncpu = cpu;
+ counter->tstamp_running += counter->ctx->time - counter->tstamp_stopped;
+ if (is_software_counter(counter))
+ counter->pmu->enable(counter);
+}
+
+/*
+ * Called to enable a whole group of counters.
+ * Returns 1 if the group was enabled, or -EAGAIN if it could not be.
+ * Assumes the caller has disabled interrupts and has
+ * frozen the PMU with hw_perf_save_disable.
+ */
+int hw_perf_group_sched_in(struct perf_counter *group_leader,
+ struct perf_cpu_context *cpuctx,
+ struct perf_counter_context *ctx, int cpu)
+{
+ struct cpu_hw_counters *cpuhw;
+ long i, n, n0;
+ struct perf_counter *sub;
+
+ cpuhw = &__get_cpu_var(cpu_hw_counters);
+ n0 = cpuhw->n_counters;
+ n = collect_events(group_leader, ppmu->n_counter - n0,
+ &cpuhw->counter[n0], &cpuhw->events[n0],
+ &cpuhw->flags[n0]);
+ if (n < 0)
+ return -EAGAIN;
+ if (check_excludes(cpuhw->counter, cpuhw->flags, n0, n))
+ return -EAGAIN;
+ i = power_check_constraints(cpuhw->events, cpuhw->flags, n + n0);
+ if (i < 0)
+ return -EAGAIN;
+ cpuhw->n_counters = n0 + n;
+ cpuhw->n_added += n;
+
+ /*
+ * OK, this group can go on; update counter states etc.,
+ * and enable any software counters
+ */
+ for (i = n0; i < n0 + n; ++i)
+ cpuhw->counter[i]->hw.config = cpuhw->events[i];
+ cpuctx->active_oncpu += n;
+ n = 1;
+ counter_sched_in(group_leader, cpu);
+ list_for_each_entry(sub, &group_leader->sibling_list, list_entry) {
+ if (sub->state != PERF_COUNTER_STATE_OFF) {
+ counter_sched_in(sub, cpu);
+ ++n;
+ }
+ }
+ ctx->nr_active += n;
+
+ return 1;
+}
+
+/*
+ * Add a counter to the PMU.
+ * If all counters are not already frozen, then we disable and
+ * re-enable the PMU in order to get hw_perf_enable to do the
+ * actual work of reconfiguring the PMU.
+ */
+static int power_pmu_enable(struct perf_counter *counter)
+{
+ struct cpu_hw_counters *cpuhw;
+ unsigned long flags;
+ int n0;
+ int ret = -EAGAIN;
+
+ local_irq_save(flags);
+ perf_disable();
+
+ /*
+ * Add the counter to the list (if there is room)
+ * and check whether the total set is still feasible.
+ */
+ cpuhw = &__get_cpu_var(cpu_hw_counters);
+ n0 = cpuhw->n_counters;
+ if (n0 >= ppmu->n_counter)
+ goto out;
+ cpuhw->counter[n0] = counter;
+ cpuhw->events[n0] = counter->hw.config;
+ cpuhw->flags[n0] = counter->hw.counter_base;
+ if (check_excludes(cpuhw->counter, cpuhw->flags, n0, 1))
+ goto out;
+ if (power_check_constraints(cpuhw->events, cpuhw->flags, n0 + 1))
+ goto out;
+
+ counter->hw.config = cpuhw->events[n0];
+ ++cpuhw->n_counters;
+ ++cpuhw->n_added;
+
+ ret = 0;
+ out:
+ perf_enable();
+ local_irq_restore(flags);
+ return ret;
+}
+
+/*
+ * Remove a counter from the PMU.
+ */
+static void power_pmu_disable(struct perf_counter *counter)
+{
+ struct cpu_hw_counters *cpuhw;
+ long i;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ perf_disable();
+
+ power_pmu_read(counter);
+
+ cpuhw = &__get_cpu_var(cpu_hw_counters);
+ for (i = 0; i < cpuhw->n_counters; ++i) {
+ if (counter == cpuhw->counter[i]) {
+ while (++i < cpuhw->n_counters)
+ cpuhw->counter[i-1] = cpuhw->counter[i];
+ --cpuhw->n_counters;
+ ppmu->disable_pmc(counter->hw.idx - 1, cpuhw->mmcr);
+ if (counter->hw.idx) {
+ write_pmc(counter->hw.idx, 0);
+ counter->hw.idx = 0;
+ }
+ perf_counter_update_userpage(counter);
+ break;
+ }
+ }
+ for (i = 0; i < cpuhw->n_limited; ++i)
+ if (counter == cpuhw->limited_counter[i])
+ break;
+ if (i < cpuhw->n_limited) {
+ while (++i < cpuhw->n_limited) {
+ cpuhw->limited_counter[i-1] = cpuhw->limited_counter[i];
+ cpuhw->limited_hwidx[i-1] = cpuhw->limited_hwidx[i];
+ }
+ --cpuhw->n_limited;
+ }
+ if (cpuhw->n_counters == 0) {
+ /* disable exceptions if no counters are running */
+ cpuhw->mmcr[0] &= ~(MMCR0_PMXE | MMCR0_FCECE);
+ }
+
+ perf_enable();
+ local_irq_restore(flags);
+}
+
+/*
+ * Re-enable interrupts on a counter after they were throttled
+ * because they were coming too fast.
+ */
+static void power_pmu_unthrottle(struct perf_counter *counter)
+{
+ s64 val, left;
+ unsigned long flags;
+
+ if (!counter->hw.idx || !counter->hw.sample_period)
+ return;
+ local_irq_save(flags);
+ perf_disable();
+ power_pmu_read(counter);
+ left = counter->hw.sample_period;
+ counter->hw.last_period = left;
+ val = 0;
+ if (left < 0x80000000L)
+ val = 0x80000000L - left;
+ write_pmc(counter->hw.idx, val);
+ atomic64_set(&counter->hw.prev_count, val);
+ atomic64_set(&counter->hw.period_left, left);
+ perf_counter_update_userpage(counter);
+ perf_enable();
+ local_irq_restore(flags);
+}
+
+struct pmu power_pmu = {
+ .enable = power_pmu_enable,
+ .disable = power_pmu_disable,
+ .read = power_pmu_read,
+ .unthrottle = power_pmu_unthrottle,
+};
+
+/*
+ * Return 1 if we might be able to put counter on a limited PMC,
+ * or 0 if not.
+ * A counter can only go on a limited PMC if it counts something
+ * that a limited PMC can count, doesn't require interrupts, and
+ * doesn't exclude any processor mode.
+ */
+static int can_go_on_limited_pmc(struct perf_counter *counter, u64 ev,
+ unsigned int flags)
+{
+ int n;
+ u64 alt[MAX_EVENT_ALTERNATIVES];
+
+ if (counter->attr.exclude_user
+ || counter->attr.exclude_kernel
+ || counter->attr.exclude_hv
+ || counter->attr.sample_period)
+ return 0;
+
+ if (ppmu->limited_pmc_event(ev))
+ return 1;
+
+ /*
+ * The requested event isn't on a limited PMC already;
+ * see if any alternative code goes on a limited PMC.
+ */
+ if (!ppmu->get_alternatives)
+ return 0;
+
+ flags |= PPMU_LIMITED_PMC_OK | PPMU_LIMITED_PMC_REQD;
+ n = ppmu->get_alternatives(ev, flags, alt);
+
+ return n > 0;
+}
+
+/*
+ * Find an alternative event that goes on a normal PMC, if possible,
+ * and return the event code, or 0 if there is no such alternative.
+ * (Note: event code 0 is "don't count" on all machines.)
+ */
+static u64 normal_pmc_alternative(u64 ev, unsigned long flags)
+{
+ u64 alt[MAX_EVENT_ALTERNATIVES];
+ int n;
+
+ flags &= ~(PPMU_LIMITED_PMC_OK | PPMU_LIMITED_PMC_REQD);
+ n = ppmu->get_alternatives(ev, flags, alt);
+ if (!n)
+ return 0;
+ return alt[0];
+}
+
+/* Number of perf_counters counting hardware events */
+static atomic_t num_counters;
+/* Used to avoid races in calling reserve/release_pmc_hardware */
+static DEFINE_MUTEX(pmc_reserve_mutex);
+
+/*
+ * Release the PMU if this is the last perf_counter.
+ */
+static void hw_perf_counter_destroy(struct perf_counter *counter)
+{
+ if (!atomic_add_unless(&num_counters, -1, 1)) {
+ mutex_lock(&pmc_reserve_mutex);
+ if (atomic_dec_return(&num_counters) == 0)
+ release_pmc_hardware();
+ mutex_unlock(&pmc_reserve_mutex);
+ }
+}
+
+/*
+ * Translate a generic cache event config to a raw event code.
+ */
+static int hw_perf_cache_event(u64 config, u64 *eventp)
+{
+ unsigned long type, op, result;
+ int ev;
+
+ if (!ppmu->cache_events)
+ return -EINVAL;
+
+ /* unpack config */
+ type = config & 0xff;
+ op = (config >> 8) & 0xff;
+ result = (config >> 16) & 0xff;
+
+ if (type >= PERF_COUNT_HW_CACHE_MAX ||
+ op >= PERF_COUNT_HW_CACHE_OP_MAX ||
+ result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
+ return -EINVAL;
+
+ ev = (*ppmu->cache_events)[type][op][result];
+ if (ev == 0)
+ return -EOPNOTSUPP;
+ if (ev == -1)
+ return -EINVAL;
+ *eventp = ev;
+ return 0;
+}
+
+const struct pmu *hw_perf_counter_init(struct perf_counter *counter)
+{
+ u64 ev;
+ unsigned long flags;
+ struct perf_counter *ctrs[MAX_HWCOUNTERS];
+ u64 events[MAX_HWCOUNTERS];
+ unsigned int cflags[MAX_HWCOUNTERS];
+ int n;
+ int err;
+
+ if (!ppmu)
+ return ERR_PTR(-ENXIO);
+ switch (counter->attr.type) {
+ case PERF_TYPE_HARDWARE:
+ ev = counter->attr.config;
+ if (ev >= ppmu->n_generic || ppmu->generic_events[ev] == 0)
+ return ERR_PTR(-EOPNOTSUPP);
+ ev = ppmu->generic_events[ev];
+ break;
+ case PERF_TYPE_HW_CACHE:
+ err = hw_perf_cache_event(counter->attr.config, &ev);
+ if (err)
+ return ERR_PTR(err);
+ break;
+ case PERF_TYPE_RAW:
+ ev = counter->attr.config;
+ break;
+ }
+ counter->hw.config_base = ev;
+ counter->hw.idx = 0;
+
+ /*
+ * If we are not running on a hypervisor, force the
+ * exclude_hv bit to 0 so that we don't care what
+ * the user set it to.
+ */
+ if (!firmware_has_feature(FW_FEATURE_LPAR))
+ counter->attr.exclude_hv = 0;
+
+ /*
+ * If this is a per-task counter, then we can use
+ * PM_RUN_* events interchangeably with their non RUN_*
+ * equivalents, e.g. PM_RUN_CYC instead of PM_CYC.
+ * XXX we should check if the task is an idle task.
+ */
+ flags = 0;
+ if (counter->ctx->task)
+ flags |= PPMU_ONLY_COUNT_RUN;
+
+ /*
+ * If this machine has limited counters, check whether this
+ * event could go on a limited counter.
+ */
+ if (ppmu->flags & PPMU_LIMITED_PMC5_6) {
+ if (can_go_on_limited_pmc(counter, ev, flags)) {
+ flags |= PPMU_LIMITED_PMC_OK;
+ } else if (ppmu->limited_pmc_event(ev)) {
+ /*
+ * The requested event is on a limited PMC,
+ * but we can't use a limited PMC; see if any
+ * alternative goes on a normal PMC.
+ */
+ ev = normal_pmc_alternative(ev, flags);
+ if (!ev)
+ return ERR_PTR(-EINVAL);
+ }
+ }
+
+ /*
+ * If this is in a group, check if it can go on with all the
+ * other hardware counters in the group. We assume the counter
+ * hasn't been linked into its leader's sibling list at this point.
+ */
+ n = 0;
+ if (counter->group_leader != counter) {
+ n = collect_events(counter->group_leader, ppmu->n_counter - 1,
+ ctrs, events, cflags);
+ if (n < 0)
+ return ERR_PTR(-EINVAL);
+ }
+ events[n] = ev;
+ ctrs[n] = counter;
+ cflags[n] = flags;
+ if (check_excludes(ctrs, cflags, n, 1))
+ return ERR_PTR(-EINVAL);
+ if (power_check_constraints(events, cflags, n + 1))
+ return ERR_PTR(-EINVAL);
+
+ counter->hw.config = events[n];
+ counter->hw.counter_base = cflags[n];
+ counter->hw.last_period = counter->hw.sample_period;
+ atomic64_set(&counter->hw.period_left, counter->hw.last_period);
+
+ /*
+ * See if we need to reserve the PMU.
+ * If no counters are currently in use, then we have to take a
+ * mutex to ensure that we don't race with another task doing
+ * reserve_pmc_hardware or release_pmc_hardware.
+ */
+ err = 0;
+ if (!atomic_inc_not_zero(&num_counters)) {
+ mutex_lock(&pmc_reserve_mutex);
+ if (atomic_read(&num_counters) == 0 &&
+ reserve_pmc_hardware(perf_counter_interrupt))
+ err = -EBUSY;
+ else
+ atomic_inc(&num_counters);
+ mutex_unlock(&pmc_reserve_mutex);
+ }
+ counter->destroy = hw_perf_counter_destroy;
+
+ if (err)
+ return ERR_PTR(err);
+ return &power_pmu;
+}
+
+/*
+ * A counter has overflowed; update its count and record
+ * things if requested. Note that interrupts are hard-disabled
+ * here so there is no possibility of being interrupted.
+ */
+static void record_and_restart(struct perf_counter *counter, long val,
+ struct pt_regs *regs, int nmi)
+{
+ u64 period = counter->hw.sample_period;
+ s64 prev, delta, left;
+ int record = 0;
+ u64 addr, mmcra, sdsync;
+
+ /* we don't have to worry about interrupts here */
+ prev = atomic64_read(&counter->hw.prev_count);
+ delta = (val - prev) & 0xfffffffful;
+ atomic64_add(delta, &counter->count);
+
+ /*
+ * See if the total period for this counter has expired,
+ * and update for the next period.
+ */
+ val = 0;
+ left = atomic64_read(&counter->hw.period_left) - delta;
+ if (period) {
+ if (left <= 0) {
+ left += period;
+ if (left <= 0)
+ left = period;
+ record = 1;
+ }
+ if (left < 0x80000000L)
+ val = 0x80000000L - left;
+ }
+
+ /*
+ * Finally record data if requested.
+ */
+ if (record) {
+ struct perf_sample_data data = {
+ .regs = regs,
+ .addr = 0,
+ .period = counter->hw.last_period,
+ };
+
+ if (counter->attr.sample_type & PERF_SAMPLE_ADDR) {
+ /*
+ * The user wants a data address recorded.
+ * If we're not doing instruction sampling,
+ * give them the SDAR (sampled data address).
+ * If we are doing instruction sampling, then only
+ * give them the SDAR if it corresponds to the
+ * instruction pointed to by SIAR; this is indicated
+ * by the [POWER6_]MMCRA_SDSYNC bit in MMCRA.
+ */
+ mmcra = regs->dsisr;
+ sdsync = (ppmu->flags & PPMU_ALT_SIPR) ?
+ POWER6_MMCRA_SDSYNC : MMCRA_SDSYNC;
+ if (!(mmcra & MMCRA_SAMPLE_ENABLE) || (mmcra & sdsync))
+ data.addr = mfspr(SPRN_SDAR);
+ }
+ if (perf_counter_overflow(counter, nmi, &data)) {
+ /*
+ * Interrupts are coming too fast - throttle them
+ * by setting the counter to 0, so it will be
+ * at least 2^30 cycles until the next interrupt
+ * (assuming each counter counts at most 2 counts
+ * per cycle).
+ */
+ val = 0;
+ left = ~0ULL >> 1;
+ }
+ }
+
+ write_pmc(counter->hw.idx, val);
+ atomic64_set(&counter->hw.prev_count, val);
+ atomic64_set(&counter->hw.period_left, left);
+ perf_counter_update_userpage(counter);
+}
+
+/*
+ * Called from generic code to get the misc flags (i.e. processor mode)
+ * for an event.
+ */
+unsigned long perf_misc_flags(struct pt_regs *regs)
+{
+ unsigned long mmcra;
+
+ if (TRAP(regs) != 0xf00) {
+ /* not a PMU interrupt */
+ return user_mode(regs) ? PERF_EVENT_MISC_USER :
+ PERF_EVENT_MISC_KERNEL;
+ }
+
+ mmcra = regs->dsisr;
+ if (ppmu->flags & PPMU_ALT_SIPR) {
+ if (mmcra & POWER6_MMCRA_SIHV)
+ return PERF_EVENT_MISC_HYPERVISOR;
+ return (mmcra & POWER6_MMCRA_SIPR) ? PERF_EVENT_MISC_USER :
+ PERF_EVENT_MISC_KERNEL;
+ }
+ if (mmcra & MMCRA_SIHV)
+ return PERF_EVENT_MISC_HYPERVISOR;
+ return (mmcra & MMCRA_SIPR) ? PERF_EVENT_MISC_USER :
+ PERF_EVENT_MISC_KERNEL;
+}
+
+/*
+ * Called from generic code to get the instruction pointer
+ * for an event.
+ */
+unsigned long perf_instruction_pointer(struct pt_regs *regs)
+{
+ unsigned long mmcra;
+ unsigned long ip;
+ unsigned long slot;
+
+ if (TRAP(regs) != 0xf00)
+ return regs->nip; /* not a PMU interrupt */
+
+ ip = mfspr(SPRN_SIAR);
+ mmcra = regs->dsisr;
+ if ((mmcra & MMCRA_SAMPLE_ENABLE) && !(ppmu->flags & PPMU_ALT_SIPR)) {
+ slot = (mmcra & MMCRA_SLOT) >> MMCRA_SLOT_SHIFT;
+ if (slot > 1)
+ ip += 4 * (slot - 1);
+ }
+ return ip;
+}
+
+/*
+ * Performance monitor interrupt stuff
+ */
+static void perf_counter_interrupt(struct pt_regs *regs)
+{
+ int i;
+ struct cpu_hw_counters *cpuhw = &__get_cpu_var(cpu_hw_counters);
+ struct perf_counter *counter;
+ long val;
+ int found = 0;
+ int nmi;
+
+ if (cpuhw->n_limited)
+ freeze_limited_counters(cpuhw, mfspr(SPRN_PMC5),
+ mfspr(SPRN_PMC6));
+
+ /*
+ * Overload regs->dsisr to store MMCRA so we only need to read it once.
+ */
+ regs->dsisr = mfspr(SPRN_MMCRA);
+
+ /*
+ * If interrupts were soft-disabled when this PMU interrupt
+ * occurred, treat it as an NMI.
+ */
+ nmi = !regs->softe;
+ if (nmi)
+ nmi_enter();
+ else
+ irq_enter();
+
+ for (i = 0; i < cpuhw->n_counters; ++i) {
+ counter = cpuhw->counter[i];
+ if (!counter->hw.idx || is_limited_pmc(counter->hw.idx))
+ continue;
+ val = read_pmc(counter->hw.idx);
+ if ((int)val < 0) {
+ /* counter has overflowed */
+ found = 1;
+ record_and_restart(counter, val, regs, nmi);
+ }
+ }
+
+ /*
+ * In case we didn't find and reset the counter that caused
+ * the interrupt, scan all counters and reset any that are
+ * negative, to avoid getting continual interrupts.
+ * Any that we processed in the previous loop will not be negative.
+ */
+ if (!found) {
+ for (i = 0; i < ppmu->n_counter; ++i) {
+ if (is_limited_pmc(i + 1))
+ continue;
+ val = read_pmc(i + 1);
+ if ((int)val < 0)
+ write_pmc(i + 1, 0);
+ }
+ }
+
+ /*
+ * Reset MMCR0 to its normal value. This will set PMXE and
+ * clear FC (freeze counters) and PMAO (perf mon alert occurred)
+ * and thus allow interrupts to occur again.
+ * XXX might want to use MSR.PM to keep the counters frozen until
+ * we get back out of this interrupt.
+ */
+ write_mmcr0(cpuhw, cpuhw->mmcr[0]);
+
+ if (nmi)
+ nmi_exit();
+ else
+ irq_exit();
+}
+
+void hw_perf_counter_setup(int cpu)
+{
+ struct cpu_hw_counters *cpuhw = &per_cpu(cpu_hw_counters, cpu);
+
+ memset(cpuhw, 0, sizeof(*cpuhw));
+ cpuhw->mmcr[0] = MMCR0_FC;
+}
+
+extern struct power_pmu power4_pmu;
+extern struct power_pmu ppc970_pmu;
+extern struct power_pmu power5_pmu;
+extern struct power_pmu power5p_pmu;
+extern struct power_pmu power6_pmu;
+extern struct power_pmu power7_pmu;
+
+static int init_perf_counters(void)
+{
+ unsigned long pvr;
+
+ /* XXX should get this from cputable */
+ pvr = mfspr(SPRN_PVR);
+ switch (PVR_VER(pvr)) {
+ case PV_POWER4:
+ case PV_POWER4p:
+ ppmu = &power4_pmu;
+ break;
+ case PV_970:
+ case PV_970FX:
+ case PV_970MP:
+ ppmu = &ppc970_pmu;
+ break;
+ case PV_POWER5:
+ ppmu = &power5_pmu;
+ break;
+ case PV_POWER5p:
+ ppmu = &power5p_pmu;
+ break;
+ case 0x3e:
+ ppmu = &power6_pmu;
+ break;
+ case 0x3f:
+ ppmu = &power7_pmu;
+ break;
+ }
+
+ /*
+ * Use FCHV to ignore kernel events if MSR.HV is set.
+ */
+ if (mfmsr() & MSR_HV)
+ freeze_counters_kernel = MMCR0_FCHV;
+
+ return 0;
+}
+
+arch_initcall(init_perf_counters);